The invention relates to seating and particularly to armrests for vehicle seats which can be adjusted to a plurality of selected parallel positions to maximize the comfort of the occupant. Examples of such armrests can be found in Hall et al U.S. Pat. No. 4,244,623, Swenson et al U.S. Pat. No. 4,165,901 and Moorhouse U.S. Pat. No. 4,311,338. Each of the aforementioned patents utilizes a 4-bar parallelogram linkage. Karlsen U.S. Pat. No. 3,489,458 and British Pat. No. 746,313 also show parallelogram linkages but offer only a single use position. Most parallelogram linkages present some possibility of finger pinching as the linkage elements are pivoted. Although the problem is minimized in covered armrests such as shown by Karlsen and Moorhouse, it is not entirely eliminated since the rear vertical clearance space between the armrest and support housing varies as the armrest is lowered.
Another disadvantage of most prior art parallel folding armrests is that they require special mountings to accommodate them to the seat frame and thus they cannot be readily adapted for use with a variety of seats which might be in a given manufacturer's line. The mounting problem can be significant since a seat frame is often quite compact while a substantial distance is usually required between the two elongated links of an armrest assembly in order to provide sufficient rigidity and strength and to accommodate the desired movement. Loading of such assemblies can be very large since the seat occupant often grabs the armrest to pull himself up from the ground and into the seat of a truck or tractor.